Sonny Boy Williamson II [as Checkin' Up On My Baby for Chess; released posthumously in '65; the only song cut by both Sonny Boy's; the first one operated from Chicago, the second one from the Delta, two separate markets then and by the time the second one moved to Chicago, the first one had died]
Taj Mahal [idem]
Mick Jagger [with The Red Devils; outtake]
Nine Below Zero [all as Checkin' Up On My Baby]
Gary Moore [as Checkin' Up On My Baby]
Not to be confused with Otis Rush's Checking On My Baby ('58 - Cobra), covered by Gregg Allman.